Why Castor Oil Is the Secret to Naturally Soft, Hydrated Lips

August 3, 2025 Tracey Bailey

When it comes to lip care, natural castor oil is having a serious moment—and for good reason. This humble plant oil, derived from the seeds of the Ricinus communis plant, is in the spotlight from skin care professionals to natural skincare lovers alike. And when used in a lip balm, castor oil is the secret to soft, smooth, hydrated lips—without the need for synthetic additives or petroleum-derived waxes.

In fact, we love it so much at Biome, we've made it the hero of our CastorGuard, CastorClear and now, our new CastorGloss Lip Conditioner—a naturally nourishing lip balm and gloss in one that you’ll never want to be without.

Here’s why castor oil deserves a starring role in your lip care routine.

What makes castor oil so good for your lips?

Castor oil is rich in ricinoleic acid, a rare fatty acid that gives it its ultra-moisturising properties. Unlike some oils that simply sit on the surface, castor oil penetrates the skin to provide deeper hydration—making it ideal for the delicate skin on your lips.

Plus, castor oil is naturally viscous meaning it provides a glossy, protective barrier without feeling heavy or greasy. It's like a built-in gloss and conditioner in one.

Benefits of castor oil for lip care

Deep hydration: Helps keep lips moisturised from the inside out.
Smooth texture: Softens roughness and improves the feel of dry lips
Natural shine: Gives lips a healthy, dewy glow without synthetic gloss agents.
Plant-based alternative: A clean, cruelty-free option to petroleum jelly and lanolin

Is castor oil better than petroleum jelly?

Petroleum jelly (petrolatum) has long been used to lock in moisture, but it doesn’t actually hydrate your lips—it simply creates a barrier. Castor oil, on the other hand, not only seals in moisture but also actively nourishes and softens.

Plus, castor oil is plant-derived, biodegradable, and renewable, whereas petrolatum is a by-product of the fossil fuel industry. That’s why more people are switching to lip balms that are free from petroleum and made with natural, effective oils like castor.

Introducing CastorGloss: The lip conditioner with a glossy twist

We created CastorGloss to harness everything wonderful about castor oil. It’s a lip balm, lip conditioner, and subtle gloss all in one—made with cold-pressed, hexane-free castor oil as the first ingredient.

To boost its benefits, we’ve added:

Coconut and jojoba oils for extra softness and glide
Antioxidant-rich strawberry seed oil, upcycled from the food industry
Plant waxes like carnauba and candelilla to lock in moisture
A hint of real vanilla bean—no synthetic fragrances or flavours

It’s vegan, petroleum-free, and handmade in Australia in small batches. And yes—a little goes a long way.

🧪 Why “hexane-free” and PEG-free castor oil matters

Not all castor oil is created equal.

Many conventional beauty products use castor oil that has been extracted with hexane—a chemical solvent derived from petroleum. Hexane speeds up the extraction process, but it can leave behind trace residues and isn’t aligned with clean beauty or low-tox living.

At Biome, we only use cold-pressed, hexane-free castor oil in CastorGloss. It’s a gentler process that maintains the oil’s beneficial nutrients—like vitamin E and ricinoleic acid—and is safer for both you and the environment.

🚫 What about PEG-40 hydrogenated castor oil?

You’ll often see PEG-40 Hydrogenated Castor Oil listed on labels—especially in conventional lip glosses, cleansers, and serums. While it starts as castor oil, it's been ethoxylated (a chemical process using ethylene oxide) and combined with petroleum-derived polyethylene glycol (PEG) compounds to make it more water-soluble.

The concerns?

PEGs can be contaminated with harmful by-products like 1,4-dioxane—a known skin irritant and possible carcinogen.
Hydrogenation doesn’t equal purity—unless you’re using pure hydrogenated castor oil (castor wax), which is simply castor oil that’s been solidified without PEGs or ethoxylation.

✅ What We Use Instead

In CastorGuard, CastorClear and CastorGloss, we use castor wax (hydrogenated castor oil) that is free from PEGs and not petroleum-derived. It adds natural structure and texture to the balm, helping it glide on smoothly and stay put—without synthetic additives.

It’s one more way CastorGloss stays true to clean, conscious beauty.

Ready to avoid petroleum and go castor?

If you’re looking for a cleaner, more effective way to keep your lips soft and healthy, castor oil is the ingredient to watch. And CastorGloss is the daily essential that lets you experience its benefits with every swipe.

🌿 Try Castor Oil for yourself!

Browse our Castor Oil Collection for clean, sustainable castor oil-based products, including:

CastorGuard—a multi-purpose balm designed for dry lips, sensitive skin, and more that's received more than 140 glowing 5 star reviews.

CastorClear—a natural vapour rub alternative.